Pioneer HPM-100 successful crossover mod!

[Gibsonian]

I suspect the HPM 100 woofer was a page taken from the Aquaplas JBL 12" L-100 woofer. To get a woofer to reach to 1600 hz is quite a feat and to keep it smooth and not beaming. So long the mid can handle the lower xover point you might well have found something that works for your taste and amplification!

I agree with you that the xover point on the woofer should be lowered and a more powerful mid to be in place. Had the HPM 100 been a 3 way I think it could have been a much better system!
DC

On all but the first HPM 100's the crossover point from woofer to mid is 3000 Hz, so if you can lower those to 1600 you are doing good. The HPM100 for all intensive purposes is a 3 way. The hpm supertweeter is 12,000 Hz and upward but at a reduced output from the rest of the drivers. The tweeter does all the work up to 19K or so. The high molecular polymer unit does not really add very much to the sound of these speakers.

 

[tinkerer]

Gibsonman....Yes the original post here was about lowering the crossover point between Woofer and Mid by replacing the 4.3uF Cap with a 10uF Cap and replacing the .6mH Coil with a .9mH Coil. The end effect being a smoother less harsh on the ears mid, along with taking some of the mid frequency load off the woofer allowing it to function better down low. At least that's my take on it. But the .9mH Coil is rather large, so I was looking into a smaller sized coil. The options I found are a .82mH or 1.0mH coil, so I was first curious as to where those would crossover, and secondly what effect the higher resistance would have. Thanks.

 

[Gibsonian]

tinkerer,

My comments were directed at the higher resistance, not the lowering the crossover point. That is why I recommended to lower resistance of your crossover components, not raise it, and place the crossover on it's own board if it is now too big to sit on the OEM board. There is an old thread on here where one of our members went all the way with this crossover rebuild using all top notch components - I will see if I can find it.

I use the HPM cabinets now but all drivers with exception of the supertweeter are changed. Before that, I biamped them using electronic crossover and lowered the crossover point to around 1200 Hz. They did sound better. It will however lower the power handling a small amount so it makes the midrange more susceptible to damage if you push them regularly in the 200 watt area. Still biamping them today but with the different drivers in there they are no longer relevant to this discussion. I cross around 1100 Hz today from an Eminence 12" to a Pioneer DSS-9 mid.

 

[Gibsonian]

Expensive components thread

http://www.audiokarma.org/forums/showthread.php?t=211542

This is the thread. If I was to do some HPM100 improvements I would likely go this route, adjusting as measurements and ear evaluations required. Unfortunately the OP does not finish his thread, don't know how it really ended.

 

[rBuckner]

How timely to stumble across this thread! I bought some HPM-100's years ago and just recently hooked them up to demonstrate some nely reworked Marantz separates for an AKer. I only had a turntable and FM as sources. I noticed two things: poor bass and harshness that only got worse with volume.

The speakers were on the floor so I figured the next thing to do for the bass was to raise them - still hasn't happened but I did jack up the front with 2 x 4s for some improvement. Standing 0-3' behind the faces of the speakers is the highest bass response.

Now I'll be reworking the crossover and reporting the results, hoping for a more pleasant sound. As a reference, I listen quite a bit to AR-11's which I love dearly but in a different sized space.

Thanks to all who chipped in thoughts all along this thread and to mattsd for starting it out. :thmbsp:

 

[daBlueslover]

I have been listening to them ever since the last post, both now having the modded crossovers in and there is absolutely no doubt, they are a 100 times better. Vocals compared to before are near life like, the midrange and treble has a definition I never heard or came close to with the original crossovers, it's almost like listening to new speakers. They are still quite bright, I have both the tweeter and midrange dialed back to -2 and further dialing back would not be out of the question. But, the harshness and blare is gone. I am quite pleased with mod and would recommend it to anyone looking to tame the harshness of there speakers.

Hey Matt I have 2 pr. of the 200watt HPM 100's. Both sound good, but one are brighter, & possibly recapped. I have not taken either pr. apart. I'd like to see if you could recap a pr. for me? If they improve over the first, then I will consider the second. I have to say I definitely think equipment specs. also impact their performance. I have been auditioning several pieces I have acquired, & there are 5 or 6 pieces that all sound spectacular, Marantz 170dc, 250 amps, Sansui AU-777A, Hafler DH-500, LUXMAN L-11, & Harmon Kardon HK-870 and I have ran through artists like The Who-Who's Next, Papa John Creach, Ruth Brown, Paul Butterfield, John Mayall, Luther Allison, Buddy Guy, Muddy Waters, Albert King, Dire Straits, SteppenWolf, Led Zeppelin, Dexter Gordon, Ben Webster, Coleman Hawkins, Ella Fitzgerald amount others, all sounding great.

 

[mattsd]

Hey Matt I have 2 pr. of the 200watt HPM 100's. Both sound good, but one are brighter, & possibly recapped. I have not taken either pr. apart. I'd like to see if you could recap a pr. for me? If they improve over the first, then I will consider the second. I have to say I definitely think equipment specs. also impact their performance. I have been auditioning several pieces I have acquired, & there are 5 or 6 pieces that all sound spectacular, Marantz 170dc, 250 amps, Sansui AU-777A, Hafler DH-500, LUXMAN L-11, & Harmon Kardon HK-870 and I have ran through artists like The Who-Who's Next, Papa John Creach, Ruth Brown, Paul Butterfield, John Mayall, Luther Allison, Buddy Guy, Muddy Waters, Albert King, Dire Straits, SteppenWolf, Led Zeppelin, Dexter Gordon, Ben Webster, Coleman Hawkins, Ella Fitzgerald amount others, all sounding great.

Send me a PM, we can talk about it there.

 

[daBlueslover]

Send me a PM, we can talk about it there.

Hey Matt
You could reach me at 661-294-3995
daBlueslover aka Dana S

 

[NEvinyl]

Hi guys. I'd like to replace all the caps, registers etc on my hpm-100's (200 watt). Does anyone have the parts I need for 2 speakers? This would my first real deal recap. I practiced desoldering and soldering on some old boards but thatshe about it. I looked at the board on the hpm and it looks very doable for the amateur that I am.

 

[Doskiez]

I love my HPM 100's. I've tryed to find better. No luck so far. Advents, AR 3a'a, Wharfedales. I believe these are an all purpose speaker though. They recreate music like no other in my opinion. Modded or not. I might try this on my other pair though just to see. I remember people talking alot about the cerwin vega back in the day. I know HPM 100's good for Rock and Roll. I wonder if maybe some old Cerwin Vega's might give them a run for their money?

Well I just ordered some parts to do this mod, plus recap the other speakers while I am in there. We shall see. Funny you mention Vegas with HPM 100s that is actually what I have set up now. I use the HPMs for all my vinyl which is mainly classic rock which they excel at so far (should be even better after the mod hopefully) and the Vegas for most modern rock, songs with a lot of bass, pretty much anything newer and heavier. I like them but they are not everyone's cup of tea, and certainly perform better with certain kinds of music than others.

 

[Copa1934]

The main issue with these networks is size. They are compact and you have to be careful of the physical size of the replacement caps. Otherwise not too bad a job, so to speak.

 

[AR44]

Hello all. I’ve spent a bunch of time looking and reading, but not commenting. For what it’s worth, thought I’d throw in a story about the HPM-100 crossover mod...as I listen to some of the best sounding speakers I have heard.

I was able to pick up a pair of the 100/200 versions a few months ago for $100CAD. They were mistreated and gruesomely eviscerated. I wasn’t even sure if I could salvage my $100. But, someone had to rescue them from the savages. These were bush party speakers, they claimed. Not hard to believe given what they looked like. One crossover was hanging out with the induction coils hanging from the soldering. All the wiring had been cut at some point or another and spliced with scrap wire. The driver leads were severed at the cone for most of the drivers. Not sure how one does that. Effectively one speaker and the super tweeters worked. That was it.

I took the woofers into a tech. Turned out they were still good. Ironically, because the leads were severed, the savaged weren’t able to do more damage to them. New leads and dust caps and they were done. I did have to visit ebay for tweeters and mids. The super tweeters, as noted were good. I pieced the crossovers back together. Purposely not recapping until everything worked. I wanted to hear them completely original first. The sound was as I remember for pioneer. The cabinets were last on the list as I wanted to know they were working first. Besides, that’s the easy part for me as wood is what I do.

They are, by the way, hooked up to a SA-7800/TX-7800 with a SG-9500 EQ. the only thing that I noticed was a slight lack of definition in the middle. It was something I was able to isolate with the EQ. Except I didn’t want to use an EQ. I didn’t 40 years ago. So why now? I did start the recap process by doing one speaker at a time. There was a subtle improvement. At this point, I was reading about this mod by mattsd.

Now don’t get me wrong. The HPM-100 stock is more than I could ask for. I was VERY happy with them and after all that work, I didn’t make the mod decision lightly. Some of its reversible with a soldering iron, but pulling the woofer coil, had the potential to forever alter the originality. I wasn’t willing to lose originality for just any mod. With trepidation, I went ahead, ordered the parts and pulled the crossover apart. One speaker at a time for comparison. The bolt did break, so no going back now on that one.

I couldn't believe what I was hearing. They do sound ‘better’. Considerably. Not different. Just better in a Pioneer HPM-100 kind of way. They still have that beloved sound. Just cleaner. More detail and definition. Especially strings and piano. I read the words “new synthesized sound is the goal” that someone used on the forum. I don’t think so.

As for the EQ, the faders were much closer to level after the mod.

I know there’s a lot of links in the sound chain between an artist with an instrument and my brain interpreting the sounds. Those links are different for everyone and every system. That chain is also different today from what it was in 1978.

In the end I will be into them for about $500CAD. With exception of the crossover mod and maybe walnut boxes, completely original. I’m good with that, knowing, that one day, I will likely be going to the grave inside them.

 

[Doskiez]

I performed this mod on a spare set of crossovers I acquired for the speakers so I could switch back to stock if needed and it made a noticeable difference, but in the best way possible. Love the sound and balance of the speakers now. Off to the next project!

 

[johnray]

I just purchased two HPM100's (200W) to use with my Sansui 717. I also purchased the caps and inductors to try the crossover mod. However unable to remove the crossover from back. Top tilts out but bottom only a little ways. Using a flashlight, seems maybe hung up with short wire to crossover. Is this a common situation? Suggestions? Thanks. John.

 

[onwardjames]

I just purchased two HPM100's (200W) to use with my Sansui 717. I also purchased the caps and inductors to try the crossover mod. However unable to remove the crossover from back. Top tilts out but bottom only a little ways. Using a flashlight, seems maybe hung up with short wire to crossover. Is this a common situation? Suggestions? Thanks. John.

Hello and welcome to AK!

I seem to remember having to wiggle my own crossovers back and forth to get clearance. It's a bit of a tight fit. Pull a woofer and work from the front if things get hairy. It's an easy job. Just be very careful with that heavy ass woofer.

 

[Schimmec]

My understanding of the technology is limited, so please forgive me if I don't get what is seemingly obvious everybody else. In xoaphexox's HPM-100 recapping walkthrough (where I originally posted this question), a bunch of people are talking about moving x-over frequencies, but no one seems to be replacing the coils. Can the crossover points be moved simply by using different capacitances when recapping? [In which case my guess is that Matt's new coil in this thread is meant for the woofer to be able to use it's lower range more effectively, which means it's not necessary for moving the crossover point, but it's better?]

I'm asking mostly because I have a pair of HPM-70s that are very similar to the 100s in build (and from what I gather: in sound), rather than to the 60s, contrary to what one might expect. For reasons of age I wanna do a recap and there are three caps to replace (0,3 / 3,0 / 6,0). Since it's hard to get a 6,0uF cap nowadays (in Europe anyways), I was wondering if I could just use a 6,8 one. If that moves the crossover point down a little bit, all the better. But I don't wanna have to replace coils as well (for the time being anyways). The x-over frequencies in the HPM-70s are 2000, 3000, 12.000, which I can live with (again: for now). Any thoughts? Thanks a lot!

[EDIT: I realize I can recreate the original capacitances by using several smaller caps in parallel and/or in series (I'm gonna have to do that with the 0,3 one anyways). Like I said, if I could also moderately move the x-over of the woofer, that would be cool, though]

 

[dc270]

You can stack caps to come pretty close to the ideal 6.0 value. Usually if you get within 10% that is tolerance for most electrolytics. Poly caps usually fall within 5% tolerance.
Good luck
DC

 

[Port Entropy]

Bumping up an old thread here (I couldn't find any more recent discussions on this exact topic).

So are people still doing this crossover mod in 2019? Are those that have done it still happy with the results?

I recently picked up a pair and am planning on recapping. I'm just trying to decide between the stock values and this mod. Any input and opinions are appreciated.

 

[Port Entropy]

I am looking at getting a parts list together for this mod. For the inductor, I am considering using a Dayton instead of the Jantzen, mostly because of the size. It sounds like some people have difficulty with the larger size of the Jantzen. The Dayton is 1.88" in diameter vs 2.05" (although it is a little taller). Seems like it would be a little easier to work with.

The specs look very similar between them.

Dayton:
Inductance: 0.90 mH • Wire gauge: 18 AWG • Core type: Air • DC resistance: 0.48 ohms • Tolerance: ±3% • Power handling: 300 watts RMS • Dimensions: 1.88" Ø x 0.63" H (47.8 x 16 mm).

Jantzen:
Tolerance: ± 3.0% • Inductance: 0.90 mH • Wire gauge: 18 AWG • DC resistance: 0.46 Ohms • Dimensions: 2.05" x 0.60" • Power handling: 300 watts RMS.

Anyone have any experience or preference with Dayton vs Jantzen inductors?

 

[Port Entropy]

I'm also trying to decide on the replacement for the 0.15uf cap. The other thread recommends the Jantzen Z-Superior, but those are out of stock. So it looks like my options are the Jantzen Z-Silver ($14.88 ea) or Audyn ($6.84).

Is the Jantzen Z-Silver worth the extra $16? I would be fine spending that if it does make an improvement, but it seems like the consensus is that the super tweeter on the HPM-100 are barely audible to most people (if at all), so I'm not sure it would matter.